Magnetic control device



Aug 21, 1951 B. L. BINFORD MAGNETIC CONTROL DEVICE Filed May 18, 1949 INVENTOR.' afym RNEYS& I I l ...Vil CLEF E lil... E E s Patented Aug. 21, 1951 Benjamin fL. Binfrd, Magneti-ol, Inc., Chi

Illinois Chicago, Ill., assignor 'to cago, Ill., 'a corporation of Application May 18, 1949, Serial No.`9`r3,'938

This 'invention relates to magnetic control ndevice and more particularly to a control device in which movement'of one magnetic elementtowa'rd and away from a complementary element y'causes the latter to move to eiTect a control unit.

AOne of the objects 'of the invention is to pro'- vide a vmagnetic control device which is simple and inexpensive to construct'and install and which is positive and reliablein operation.

`Another object is to provide a magnetic Vc'ontrol device in which a movable magnet 'mounted on V-one :side `of a non-magnetic wall portion v'is attracted and released by an larmature movable linearly toward and away from the other rside l'of the wall portion. In a typical installation the l vwall portion is horizontal with the "magnet carried by `a pivoted head above it and vwith the armature moved vertically towardand away from the bottom of the wall portion by a Aliquid displa'cer or similar actuator.

Still another object is to Yprov-ide a 5magnetic cori-trol device in 'which a vlost-motion 'connection is provided between the actuator and v'theflinearly movable armature. In thepreferred construction the 'armature is carried by a tube and is actuated by rva 'rod slida'ble vin the Etube and having a 'pin engageable with adjustable abutment's on the 'The above and other objectsandadvantages of the invention will be more readily apparent when Y cludes a mounting or supporting plate II to ylit over an opening in the tank top wall ran'd to be secured in sealed relation thereto by mounting screws I2. rlhe plate II is 'annular and .carries at its central part a plate or `wall portion .I3 of non-magneticmaterial `such as brass.

,Above the plate 'I3 there vis pivotally supported ,head a plate y7 Claims. (Cl. 172-284) 'raise and lower the laetuatr I4 carrying a permanent magnet I5 at one end with the poles of the mag-net facing downward. The plate I4 is supported by an upright an'ge I6 formed from a sheet II overlying the `plate II and having upwardly extending ears I8 to Vfit into notches inthe ysides of the vplate I4. Aspring I9 is connected to the free end of the plate 14 to urge it downward to raise ythe 'magnet I5. Y

A frame 2l may be mounted above the plate I3 to carry a terminal block 22 connected to a pair of tiltable mercury switches 23 supported v'on fthe head I4. While two switches are shown, it .will be understood 'that only a single 'switch or more than two switches `could be used, as desired. Connections from the terminal block may extend through an opening 24 to 'suitable external 'c'ontrol or indicating devices. The entire mechansm as so far described is enclosed 'ina cover 2'5 secured by screws 26 to the plate II.

On its lower surface the plate I I carries afguide structureZvI which is shown as a cup shaped stamping bolted at its upper opening 'edge to the bottom of the plate I l and having a central :guide hole in its lower end dened by an annular raised ridge 28 to serve a spring centering device. vA sleeve 29 extends vslidably through the opening in the guide 2'I and is of a length to project below theguide when its upper end is adjacent the plate I3. At its upper end the tube carries Va magnetic: armature 3| which will register `with the magnet I5 when the tube is in its elevated position.

The .tube slidably receives an elongated actuator rod 32 which extends vertically into the tube and which carries at spaced points zin .its length a pair of tcrossed :pins 33 and '34. The .ends of the pins extend through slots 35 in the sides of the tube and beyond the outer surface :of the tube. The-pin 3.3 engages a collar 36 which -is .slidable on the 'tube and which is Vurged upward by `a spring 43'I centered by the projection 128. Since the pin 33 is freely slidable relative to the sleeve, it will be seen Vthat the spring urges the lactuator' rod V32 'upwardwithout aecting the 'sleeveforfthe armature.

To move the armature, the actuator rod 32 carries a pair of spaced liquid 'displacers 38 which function as more particularly described and claimed in my copending application Serial -No. 93,937, led 'May 18, 1949. :These displaeersivilll fluctuations in liquid level in the tank to raise and lower the pin 34. The lower portion of the sleeve 29 is threaded as shown adjustably to receive a pair of stop nuts 39 positioned on opposite sides of the pin 34 to be engaged by the pin as it moves. The stop nuts may be adjustably set any desired distance apart to provide any desired extent of lost motion between the rod 32 and the sleeve 39.

With the parts in the position shown, the armature 3l is raised to attract the magnet I5 which is lowered to rock the head I 4 counter-clockwise. This willtilt the mercury switches 23 to the left and in the case of the switch shown in Figure 1 will cause it to open. It will be understood that the other switch could be closed, if desired, and that any arrangement for opening or closing the switches in accordance with movements of the liquid displacers could be provided. The sleeve and armature will be held up in the position shown by attraction of the magnet on the armature even though the pin 34 has moved away from the upper stop nut 39.

If the liquid level falls, the displacers will move downward until the pin 34 engages the lower stop nut 39. Further continued downward movement will pull the armature away from the plate I3 decreasing the magnetic attraction between the armature and the magnet until the spring I9 raises the magnet and rocks the head counterclockwise. At this time the switches 23 will be tilted to the right to the opposite circuit control position from that shown in Figure 1.

The parts will remain in this position until the displacers have again been elevated suiliciently to bring the pin 34 into engagement with the top stop nut 39. After this occurs, further upward movement of the displacers will raise the sleeve 29 and the armature 3l. When the armature 3| approaches the plate I3 closely, the attraction between it and the magnet will become suicient to rock the head I4 to the position shown, thereby tilting the switches 23 to effect the desired indicating or control operation. By adjustment of the spacing between the stop nuts 39, the amount of lost motion between the actuating rod and the armature can be adjusted to produce the desired control operation. It will be seen that the entire structure can be fabricated and assembled simply and inexpensively, and when installed will provide a highly reliable and positive type of operation.

While one embodiment of the invention has been shown and described in detail herein, it will be understood that this is illustrative only and is not to be taken as a denition of the scope of the invention, reference being had for this purpose to the appended claims.

: What is claimed is:

1. A magnetic control device comprising a support having a substantially horizontal non-magnetic wall portion, a head pivoted on a horizontal axis above the wall portion and having a magnetic pole movable toward and away from the wall portion, means yieldingly urging the head in a direction to move the pole away from the wall portion, a magnetic armature below the wall portion, a tubular sleeve connected to the armature to guide it for vertical movement toward and away from the wall portion, an actuator rod slidable in the sleeve, and a lost motion connection between the rod and the sleeve.

2. A magnetic control device comprising a support having a substantially horizontal non-magnetic wall portion, a head pivoted on a horizontal '4 axis above the wall portion and having a magnetic pole movable toward and away from the wall portion, means yieldingly urging the head in a direction to move the pole away from the wall portion, a magnetic armature below the wall portion, a tubular sleeve connected to the armature to guide it for vertical movement toward and away from the wall portion, an actuator rod slidable in the sleeve, a pin on the rod projecting through a slot in the sleeve, and spaced adjustable stop nuts on the sleeve engageable with the pin to provide a lost motion connection between the rod and the sleeve.

3. A magnetic control device comprising a support having a substantially horizontal non-magnetic wall portion, a head pivoted on a horizontal axis above the wall portion and having a magnetic pole movable toward and away from the wall portion, means yieldingly urging the head in a direction to move the pole away from the wall portion, a magnetic armature below the wall portion, a tubular sleeve connected to the armature to guide it for vertical movement toward and away from the wall portion, an actuator rod slidable in the sleeve, a' spring connected to the rod urging it in one direction, a liquid displacer connected to the rod to urge it in the other direction, and a lost motion connection between the rod and the sleeve.

4. A magnetic control device comprising a support adapted to be mounted in the top of a tank and having a horizontal non-magnetic wall portion, a guide extending below the horizontal wall portion, an elongated tubular` member slidably supported by the guide for vertical movement toward and away from the wall portion, a magnetic armature carried by the tubular member adjacent its upper end, an actuator rod slidable in the tubular member, and a lost motion connection between the rod and the tubular member.

5. A magnetic control device comprising a support adapted to be mounted in the top of a tank and having a horizontal non-magnetic wall portion, a guide extending below the horizontal wall portion, an elongated tubular member slidably supported by the guide for vertical movement toward and away from the Wall portion, a magnetic armature carried by the tubular member adjacent its upper end, an actuator rod slidable in the tubular member, a pin on the actuator rod projecting through a slot in the tubular member, and

spaced'stop means on the tubular member engageable with the pin to form a lost motion conlroiection between the rod and the tubular memer. 6. A magnetic control device comprising a support adapted to be mounted in the top of a tank and having a horizontal non-magnetic wall portion, a guide extending below the horizontal wall portion, an elongated tubular member slidably supported by the guide for vertical movement toward and away from the wall portion, a magnetic' armature carried by the tubular member adjacent its upper end, an actuator rod slidable in the tubular member, a spring urging the rod in one direction, a liquid displacer connected to the rod to urge it in the other direction, and a lost motion connection between the rod and the tubular member.

7. A magnetic control device comprising a support adapted to be mounted in the top of a tank and having a horizontal non-magnetic wall portion, a guide extending below the horizontal wall portion, an elongated tubular member slidably supported by the guide forvertical movement to-f Ward and away from the wall portion, a magnetic armature carried by the tubular member adjacent its upper end, an actuator rod slidable in the tubular member, the tubular member having an elongated axial slot therein, a pair of pins on the rod projecting through the slot, a coil spring around the tubular member engaging one of the pins and the guide to urge the rod upward, a liquid displacer on the rod to urge it downward, and spaced nuts threaded on the tubular member and engageable with the other pin to form a 10st motion connection between the rod and the tubular member.

' BENJAMIN L. BINFORD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 706,505 Washington Aug. 5, 1902 1,193,744 Wilkinson Aug. 8, 1916 2,084,051 Van Vulpen June 15, 1937 2,236,360 Beam Mar. 25, 1941 2,300,300 Lund Oct. 27, 1942 

